Medulloepithelioma is a rare tumour with a very poor prognosis. The most frequent site in the central nervous system is the cerebral hemispheres. Appearances on MRI are very variable, possibly ...reflecting the divergent forms of differentiation seen at histological examination. We report a rare case of sellar and suprasellar medulloepithelioma in a 2-year-old boy and discuss the imaging, differential diagnosis and pathologic findings.
The present paper examines the relationship between development of various kinds of generic competencies, and its association with secondary public examination performance, using a case study of ...tertiary STEM freshmen in Hong Kong. The result shows different trajectories of generic competencies development between STEM and non-STEM students prior to their entrance to tertiary education. The findings also show that Liberal Studies, as a key public examination subject, has positive association with the development of both creative thinking as well as critical thinking among STEM students.
Approximately 5% of people with human immunodeficiency virus type 1 (HIV-1) infection remain free of disease for 10 or more years. These long-term nonprogressors (LTNPs) exhibit lower viral loads and ...stable CD4+ lymphocyte counts. The immunologic basis for this disease-free condition is not known. Because cytotoxic T lymphocytes (CTLs) constitute a major immune defense mechanism for sustained recovery from viral infections, we analyzed HIV-specific CTL responses in three asymptomatic LTNPs. We observed the presence of HIV-1 envelope-specific CTL responses mediated by HLA class I C-restricted CD8+ cells in these individuals. Using autologous target cells and a panel of HLA-matching and -mismatching B-cell lines as targets, we determined that HLA-Cw7 is the restricting element for the observed CTL activity. Additionally, we identified three peptides, one previously not reported, from conserved regions in the envelope protein as CTL epitopes. We previously reported these peptides to be efficient in inducing HIV-specific cellular immune responses in murine and nonhuman primate models. Our results support the role of the HLA-C locus in generating CTL responses and constitute the first report of an HLA-Cw7-restricted HIV-1 envelope-specific CTL response in HIV+ LTNPs, which may be important in the control of HIV replication in vivo.
A 100-amino-acid DNA-binding motif, known as the winged helix, was first identified in the mammalian hepatocyte nuclear factor-3 (HNF-3) and
Drosophila fork head family of transcription factors. ...Subsequently, more than 40 different genes that contain the winged helix motif have been identified. In the studies described here, we have determined the murine chromosomal location of eight members of this gene family, HFH-1, HFH-3, HFH-4, HFH-5, HFH-6, HFH-8, BF-1, and BF-2, by interspecific backcross analysis. These genes, designated HNF-3 fork head homolog 1 (
Hfh1),
Hfh3, Hfh4, Hfh5, Hfh6, Hfh8, Hfh9, and
Hfh10, respectively, mapped to 6 different mouse autosomes and are thus well dispersed throughout the mouse genome. Based on this mapping information, we predict the chromosomal location of these genes in humans and discuss the potential of these genes as candidates for uncloned mouse mutations.
In plasma membranes derived from bovine mesenteric lymphatic smooth muscle cells, guanine nucleotide and forskolin stimulated adenylyl cyclase (AC) activity in a concentration-dependent manner, ...indicative of the presence of the stimulatory G-protein G, linked to AC. There was no significant enzyme inhibition by low concentrations of guanine nucleotide and no effect on basal or guanine nucleotide-stimulated activity following pertussis toxin treatment of cells, suggesting the absence of G, linked to inhibition of AC. Furthermore, there was no effect of adrenaline, isoprenaline or clonidine on basal or forskolin-stimulated activities, nor was there any specific binding of the β-adrenoceptor ligand
125Icyanopindolol to membranes, suggesting that catecholamine receptors do not modulate AC activity in these membranes. Pertussis toxin-mediated ADP ribosylation of membrane proteins and Western immunoblotting analysis revealed the presence of G-protein subunits of G
αi2, G
αq, G
α11 and G
β1. In experiments designed to identify a possible effector enzyme for these G-proteins, membranes were screened with a range of antibodies raised against phospholipase C (PLC) β, γ and δ isozymes. Though no evidence was obtained by Western blotting for any of these proteins, PLC activity was concentration-dependently stimulated by Ca
2+, but not by AlF
4-, GTPS, or purified G
βγ subunits. Finally, no specific binding to membranes of the
α
1-adrenoceptor ligand
3Hprazosin or the
α
2-adrenoceptor ligand
3Hyohimbine was obtained. In conclusion, this study provides evidence for a G
s-dependent stimulation of AC, and for the presence of G
i2 and G
q/11, which do not appear to regulate a PLC activity also identified in lymphatic smooth muscle cell membranes. Furthermore, neither AC nor PLC appear to be associated with catecholamine receptors.
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